Self-locking nut



SELF-LOCKING NUT Filed July 9, 1945 INVENTOR ATTORNEYS Patented Aug. 28, 1945 SELF-LOCKHN'G NUT I Childress B. Gwyn, Jr., Bannockburn, Hi, as-

slgnor, by mesne assignments, to Smaller War Plants Corporation, New York, N. Y., a corporation or the United States Application July 9, 1943, Serial No. 493,992

2 Claims.

This invention relates to self-locking nuts. A self-locking nut now On the market comprises a casing in the form of a cup having a flat bottom provided with an aperture and having the side wall of polygonal contour to define a polygonal socket.

within the casing and have their peripheries so shaped as to fit the inside of the casing. Each wall portion terminates in a tapering integral tab, the base of which is co-extensive with the top edge of the corresponding wall portion and such tabs are intumed over the locking member to retain the locking member and the nut member in the socket.

In this nut, the locking member which usually is composed of fiber, is exposed over a considerable portion of its area to atmosphere, particularly before its assembly with a bolt. Not infrequently, the action of atmosphere on the fiber locking member so afiects it that it has a tendency to loosen and rotate within the casing during assembly of the nut on a bolt. Also, after assembly with the bolt, part of the area of the lock ing member is still exposed to any mechanical and/or abrasive and/or humidity and or corrosive conditions present and such conditions may considerably shorten the useful life of the nuts.

An object of this invention is a self-locking nut in which the fiber locking member is provided with a metal protector which in addition assists in firmly securing the fiber locking member against rotation in the shell.

Other objects, novel features and advantages oi this invention will become apparent from the following specification and accompanying drawing, wherein:

Fig. l is a section through one embodiment of the nut, and.

Fig. 2 is a section through'a second embodiment of the nut.

A nut embodying this invention comprises a sheet metal cup or casing Ill formed in such a manner as to have a fiat bottom I l and a series of flat wall portions l2 defining a polygonal socket with the fiat portions !2 forming surfaces on which a wrench may obtain a grip. The bottom of the cup is provided with an aperture [3 and the upper edge is scalloped or otherwise provided withlextending tapered portions or tabs M which are adapted to be inturned as later to be described.

After the formation of the casing, a nut member 15 is inserted therein in contact with the casing bottom and a locking member i6 is placed on thenut member. Preferably, the nut member.

A metal nut member and a preferably elastic locking member are positioned.

and the locking member'are of the same shape as the interior of the casing but of smaller area. I

The bore of the nut member I5 is threaded while the bore of the locking member it is smooth and of less diameter'tha'n the major diameter of the nut member thread. The locking member 16 may be of material known as vulcanized fiber, Bakelite, rubber or other elastic and relatively tough material of like nature.

' A fiat-bottom cup-shaped shell I! is arranged I within the casing ill with its rim engaging the bottom of the casing and with its wall interposed between the exteriors of the nut member l5 and locking member It and the interior of the casing II. The exterior wall of the shell ll preferably is of the same polygonal contour as the casing l0 so as to be held against rotation therein and the interior wall is of suitable shape and size snugly to receive the nut and locking members i5 and I6 respectively. In the bottom of the shell I1 is a central aperture of slightly larger area than the bore of the locking member 16.

After location of the not and locking members I4 and i5 and the shell I! within the casing H), the tabs l4 are inturned over the bottom of the shell H by any suitable mechanism. Preferably,

sufllcient pressure is applied to the tabs to cause the inner edges thereof to press in on and render concave the bottom of the shell ll. Such concavity exerts a spring pressure on the locking member I6 further binding it in place and also affords a protective facing. A resilient member it may be interposed between the nut member and locking member to assist in retaining a secure grip thereon.

In the modification illustrated in Fig. 2, the arrangement of the nutand locking members I5 and it is reversed. The locking member I6 is located in contact with the bottom ii of the casing i2 while the nut member I5 is arranged to be engaged by the bottom of the shell H. The tabs M are inturned against the bottom of the shell ll and are forced inwardly suiiicient to render concave the bottom of the shell as previously described.

While a resilient. member 18 is shown in the drawing and described in the specification, it is to be understoodthat the invention contemplates the omission of this member. The nut of this invention may consist merely of the nut and lockhas members within the shell H in turn received within the casing Ill and the tabs bent over thebottom thereof. Also, it is to be understood that ture above described without in anyway departing from the spirit oi the invention as defined in the appended claims.

I claim:

1. A self-locking nut comprising a flat bottom cup-shaped casing having a central aperture and being oi polygonal interior and exterior contour, a flat bottom cup-shaped shell within said casing with its rim racing the casing bottom, said shell being of po gonal interior and exterior contour with its exterior contour being complemental to the interior contour of said casing to prevent rotation of said shell relative to said casing, a nut member and a locking member within said shell, said members being of external polygonal contour complemental to the interior of said shell to prevent rotation of said members relative to said shell, and extensions from said casing wall bent inwardly over said shell bottom to retain it, together with the nut and locking members, in said casing, an aperture in said shell bottom, a tapped aperture in said nut member and an aperture in said locking-member, said locking member aperture being of less diameter than the major diameter 01' said tapped aperture and said shell aperture being only slightly larger than the locking member aperture whereby the face of the locking member is substantially covered by said shell bottom.

2. A self-locking nut according to claim 1 characterized by resilient means interposed between said nut and locking members.

CHILDRESS B. GWYN. JR. 

